Bone graft cage

ABSTRACT

A device for containing bone graft material includes an outer sleeve including a first proximal longitudinal split extending along a length thereof and a first distal longitudinal split extending along a length thereof and an inner sleeve connected to the outer sleeve via at least one strut so that a bone graft collecting space is defined therebetween, the inner sleeve including a second distal longitudinal split extending along a length thereof in combination with an interstitial mesh extending circumferentially between the inner and outer sleeves to hold graft material in the bone graft collecting space, the interstitial mesh including a third longitudinal split extending along a length thereof so that a distal side of the device may be spread open to open the distal longitudinal slot from the outer sleeve, through the interstitial mesh and the inner sleeve to a space radially within the inner sleeve.

PRIORITY CLAIM

The present application is a Continuation of U.S. patent applicationSer. No. 15/617,864 filed on Jun. 8, 2017, now U.S. Pat. No. 10,507,110;which claims priority to U.S. Provisional Application Serial No.62/349,470 filed on Jun. 13, 2016. The disclosures of the aboveapplication(s)/patent(s) are expressly incorporated herein by reference.

BACKGROUND

Large bone defects are often treated with implants and/or bone grafts toassist with healing. The bone grafts may be placed in the target areausing any of a variety of methods. For example, a graft may simply beplaced between two separated ends of an injured or otherwise damagedbone. However, without a container for the bone graft, the graft mayfall away from a target site before it can be incorporated by the bodyinto the healing bone. According to another method, PMMA spacers may beplaced in the target area so that the fibrous tissue may be formedwithin the spacers. Subsequently, the PMMA spacers are removed and bonegraft material is packed into the capsule formed by the body.Alternatively, some methods have included a mesh placed into the targetarea to contain the bone graft material at that location. These meshcontainers generally include an outer wall with a diameter selected tomatch an outer surface of the bone to prevent the graft material fromfalling out of the bone.

SUMMARY OF THE INVENTION

The present invention is directed to a device for containing bone graftmaterial including a outer sleeve extending longitudinally from a firstend to a second end, the outer sleeve including a first proximallongitudinal split extending along a length thereof and a first distallongitudinal split extending along a length thereof and a inner sleeveconnected to the outer sleeve via at least one strut so that a bonegraft collecting space is defined therebetween, the inner sleeveincluding a second distal longitudinal split extending along a lengththereof in combination with an interstitial mesh extendingcircumferentially between the inner and outer sleeves to hold graftmaterial in the bone graft collecting space, the interstitial meshincluding a third longitudinal split extending along a length thereof toform a distal longitudinal slot along the length of the device so that adistal side of the device may be spread open to open the distallongitudinal slot from the outer sleeve, through the interstitial meshand the inner sleeve to a space radially within the inner sleeve.

BRIEF DESCRIPTION

FIG. 1 shows a perspective view of a graft containment device accordingto an illustrative embodiment;

FIG. 2 shows a cross-sectional view of the device of FIG. 1;

FIG. 3 shows an end view of the device of FIG. 1;

FIG. 4 shows an enlarged perspective view of the device of FIG. 1;

FIG. 5 shows an enlarged perspective view of a graft containment deviceaccording to an alternate embodiment;

FIG. 6 shows a perspective view of a graft containment device accordingto a further embodiment partially inserted over an intramedullary rodbetween two separated portions of bone;

FIG. 7 shows a perspective view of the graft containment device of FIG.6, in a desired final position between the two separated portions ofbone;

FIG. 8 shows a perspective view of the graft containment device of FIG.6 with an outer sleeve thereof spread open; and

FIG. 9 shows an end view of the graft containment device of FIG. 6 withthe outer sleeve thereof spread open and a longitudinal slot thereofpartially opened.

DETAILED DESCRIPTION

The present invention may be further understood with reference to thefollowing description and the appended drawings, wherein like elementsare referred to with the same reference numerals. The present inventionrelates to the treatment of bone defects and, in particular, relates totreatments using bone graft material. Exemplary embodiments of thepresent invention describe a graft containment device configured to bepositioned between separated longitudinal portions of a bone such thatgraft material may be packed therein so that healing may progress as thegraft material is incorporated into new bone joining the separatedportions of bone. The graft containment device of the exemplaryembodiment comprises an arrangement of slots that permit a distal sideof the device to be opened radially to permit insertion to a desiredspace between separated portions of bone over an intramedullary deviceso that the intramedullary device is received within an inner sleeve ofthe device. The outer sleeve of the device may then be radially openedon a proximal side (facing the user) to pack graft material into a spacebetween the outer and inner sleeves. Those skilled in the art willunderstand that the term proximal, as used in this application, refersto a part of an item that is closer to or facing a user of the devicewhile the term distal refers to a part of an item that is further fromor facing away from a user. The device of the present invention isgenerally for use in treating non-articular portions of long bone suchas, for example, the femur, tibia and humerus.

As shown in FIGS. 1-4, a graft containment device 100 according to anexemplary embodiment of the present invention comprises an outer sleeve102 and an inner sleeve 104 connected to one another so that, when thedevice 100 is positioned in a target area between separated longitudinalportions of a target bone, the outer sleeve 102 substantially matches aprofile of the outer surface of each of the separated portions of bonewhile the inner sleeve 104 substantially matches a profile of amedullary canal of the target bone and/or a shape of ends of theseparated portions of the target bone. The device 100 also comprises aninterstitial mesh 106 extending radially outward from an exteriorsurface 108 of the inner sleeve 104. The interstitial mesh 106 and theinner sleeve 104 hold graft material packed therein between the outerand inner sleeves 102, 104 and prevent migration of the device 100 alongthe length of the bone once the device 100 has been positioned in thetarget area between the separated portions of bone. The outer sleeve102, inner sleeve 104 and the interstitial mesh 106 of the device 100are formed via a strut framework so that the device 100 may be threedimensionally built (e.g., by 3-D printing) using patient specific bonedimensions, which may be obtained, for example, via 3D imaging of thetarget bone. In particular, circumferential and/or axial driver curves,along with a desired spacing between adjacent struts, may be used asinput data for building and printing the device 100.

The outer sleeve 102 extends longitudinally from a first end 110 to asecond end 112 and, in this embodiment, defines a generally cylindricalshape corresponding to the profile of the outer surface of the targetbone. The device 100 includes a distal longitudinal slot 114 extendingradially through the outer and inner sleeves 102, 104, respectively,along an entire length of the device 100 so that the device 100 may beopened to be slid over a medullary rod (or other insert) extendingbetween the separated segments of bone. This permits the device 100 tobe slid directly over the rod between the separated segments of bone sothat the rod ends up radially within an inner space 115 defined by theinner sleeve 104. In other words, struts 116 and 116′ extend from theinner sleeve 104 to the outer sleeve 102 and are separatedcircumferentially from one another to define the longitudinal slot 114.Those skilled in the art will understand that the device 100 may includeany number of struts 116 and 116′ separated from one anotherlongitudinally along the length of the device 100 (i.e., from the firstend 110 to the second end 112) to sufficiently couple the inner sleeve104 to the outer sleeve 102 while permitting the device 100 to opencircumferentially as desired. In this embodiment, the struts 116, 116′form the only connection between the outer sleeve 102 and the innersleeve 104. This permits the outer sleeve 102 to be openedcircumferentially to a large extent to facilitate the packing of graftmaterial therein. However, those skilled in the art will understand thatadditional connections may be made at selected points around thecircumference of the device 100 to enhance the structural integrity ofthe device although this may reduce the amount by which the outer sleeve102 may be spread open to pack the graft material therein. Thus, thedevice 100 may be spread open at the slot 114 to permit anintramedullary rod or other implant to be slid into the device 100 aswill be described in more detail below. As will be understood by thoseskilled in the art, the first and second ends 110, 12, respectively, ofthe outer sleeve 102 of this embodiment are separated by a distancesubstantially equal to a distance by which the portions of bone areseparated. As would be understood by those skilled in the art, the firstand second ends 110, 112 need not be flat and do not need to have thesame general shape. Each of the first and second ends 110, 112 may takeany shape necessary to conform to the shape of the end of the separatedportion of bone to which it will be adjacent. This allows the outersleeve 102 and the inner sleeve 104 to abut ends of both of theseparated segments of bone. However, alternatively, a length of theouter sleeve 102 may extend slightly beyond the length of the innersleeve 104 so that the outer sleeve 102 over laps one or both of theends of the separated portions of bone. The device 100 according to thisembodiment also includes a projection 120 at each of the first andsecond ends 110, 112, respectively, with each of the projections 120including a hole through which a screw or other fastener may be insertedto couple the device 100 to the bone. Those skilled in the art willrecognize that either or both of these projections 120 may be omitted infavor of other means for securing the device 100 to the bone.

The device 100 according to this embodiment also includes an inner slot118 formed in the inner sleeve 104 diametrically opposed to the slot114. This inner slot 118 enhances the ability of the inner sleeve 104 tospread circumferentially permitting the device 100 to be more easilyopened to the extent necessary to facilitate the insertion of the device100 over a medullary rod. Those skilled in the art will understand thatthis inner slot 118 is optional and may be omitted in any device that issufficiently flexible to accommodate a medullary rod or other implantwith which it is to be employed without the slot 118. Specifically, theslot 114 allows a surgeon to insert the device 100 with the distal side124 of the device 100 (including the slot 114) facing the bone. Thesurgeon may then spread the distal side 124 of the device 100 opencircumferentially to slide the device 100 over an intramedullary rod andinto position between the separated portions of bone. During insertion,the proximal side 122 of the device 100 faces the surgeon who may thenuse proximal slot 126 to spread open the outer sleeve 102 so that he maypack bone graft material into the annular space 128 between the outerand inner sleeves 102, 104, respectively, from the proximal side of thedevice 100.

Specifically, to properly insert the device 100 into the space betweenportions of a bone separated from one another longitudinally (i.e.,along an axis of the bone) when a medullary rod extends between theseportions of bone, the distal side of the device 100 is openedcircumferentially via the distal slot 114 and the intramedullary rod ispassed through the slot 114 until it enters the inner space 115 withinthe inner sleeve 104. The surgeon then allows the device 100 to closecircumferentially (e.g., under its natural bias or by pushing itclosed). Those skilled in the art will understand that, after the device100 has been positioned as desired, it will be held in the closedposition by the surrounding soft tissues. In addition, after theprocedure has been completed, the proximal side 122 of the device 100may then be closed, for example, by suturing. After the device 100 hasbeen positioned as desired (but before the proximal side 122 of thedevice 100 is sutured closed, the surgeon then spreads the outer sleeve102 open circumferentially by spreading apart the halves of the outersleeve 102 separated by the proximal slot 126. This permits the surgeonto pack the annular space 128 with bone graft material or, if the spacewas already packed with graft material, to supplement this material withadditional graft (e.g., to replace any material that may have been lostas the device 100 was positioned).

The outer sleeve 102 is coupled to the struts 116 and 116′ at joints130, 130′ that are formed to permit the outer sleeve 102 to flex andpivot relative to the struts 116, 116′. That is, the joints 130, 130′permit the halves of the outer sleeve 102 to rotate relative to thestruts 116, 116′, respectively, when the surgeon spreads the halves ofthe outer sleeve 102 apart circumferentially to open the slot 126. Aswould be understood by those skilled in the art, the joints 130, 130′ inthis embodiment form a living hinge to permit the desired rotation ofthe outer sleeve 102 relative to the struts 116, 116′. The struts 116,116′ of this embodiment are also connected to the interstitial mesh 106so that, when the halves of the outer sleeve 102 are spread away fromone another at the slot 114, the entire device is spread open—i.e., theouter sleeve 102, the interstitial mesh 106 and the inner sleeve 104 arespread open so that an intramedullary rod may be passed all the way tothe space 115 within the inner sleeve 104.

As would be understood by those skilled in the art, the outer sleeve 102is built via a strut framework so that the outer sleeve 102 is formed ina mesh configuration. The mesh configuration of the outer sleeve 102 ofthe embodiment shown in FIGS. 1-4 includes circumferential struts 131and axial struts 132 intersecting one another. Adjacent circumferentialstruts 130 and adjacent axial struts 132 may be separated from oneanother by a distance of between 0.4 mm to 10.0 mm or any other distancedesired that will provide the desired structural integrity of the device100 and a desired level of containment for the graft material therein.The circumferential and axial struts 131, 132 may intersect one anotherto form any of a variety of mesh patterns. In one embodiment, thecircumferential and axial struts 131, 132 may intersect one another toform a substantially grid-like pattern. In another embodiment, as shownin FIG. 1, circumferential struts 131 may be connected to one anothervia axial struts 132, which are alternatingly interrupted along a lengththereof to form a staggered mesh pattern. The staggered mesh pattern maybe particularly useful for controlling both the containment of the graftmaterial between the inner and outer sleeves 104, 102 as well as aflexibility of the device 200. A distance between adjacentcircumferential struts 131 controls the containment of the graftmaterial while the alternating axial struts 132 adjacent circumferentialstruts 131 control the flexibility (e.g., torsional and axial) of thedevice 100. The axial struts 132 prevent buckling of the device 100.

In particular, the axial struts 132 are interrupted between adjacentcircumferential struts 131 so that openings defined by the interestingstruts 131, 132 are offset from one another about a circumference of thedevice in a staggered pattern. This permits portions of adjacentcircumferential struts 131 extending between connecting axial struts 132to be compressed toward one another to provide axial and/or torsionalflexibility. Thus, the larger the distance between axial struts 132, thegreater the flexibility. In one embodiment, the distance betweenadjacent axial struts 132 may be larger than a distance between adjacentcircumferential struts 131. It will be understood by those of skill inthe art, however, that a distance between adjacent struts may be varied,as desired, and is not required to be constant along an entire lengthand/or about an entire circumference of the device 100. As would beunderstood by those skilled in the art, the inner sleeve 104 may beconstructed in the same manner including circumferential and axialstruts with a similar or different separation as desired.

As described above, the length of the outer sleeve 102 may be selectedso that first and second ends 110, 112 of the outer sleeve 102 abut theseparated ends of the target bone or so that the ends 110, 112 overlapthe separated ends of the target bone by a desired length. In addition,one or both of the ends 110, 112 may include a screw receiving structure134 projecting axially away from the corresponding one of the ends 110,112 to position a screw hole 136 thereof at a desired position on thecorresponding portion of the target bone. In addition, the device 100may include a tag 138 connected to the outer sleeve 102 via a separablestrut 140. As would be understood by those skilled in the art, the tagmay display any desired information (e.g., information as to whether oneor more cages are to be used, lot number, surgeon name, etc.) while alsoindicating a desired implantation position (e.g., via text and/or shapewith a pointed end of the tag facing a superior end of the bone), aswell as a desired orientation with respect to rotation of the device 100about its longitudinal axis (e.g., with the tag 138 being mounted on aproximal side 122 of the device 100). When the device 100 has beenpositioned as desired, the tag 138 may be separated from the device 100(e.g., by snipping the strut 140).

The inner sleeve 104 is connected to the interstitial mesh 106 via aplurality of members 144 so that the inner and outer sleeves 104, 102are separated from one another via the annular space 128. The innersleeve 104 extends longitudinally from a first end 146 to a second end148 and, as described above, defines a shape substantially correspondingto a medullary canal of the target bone and has a length substantiallycorresponding to the distance of separation between the separatedportions of bone. As would be understood by those skilled in the art,wherein length of the outer sleeve 102 is selected to be equal to adistance between the separated portions of bone, the inner sleeve 104and the outer sleeve 102 with have the same length. If the outer sleeve102 is lengthened to overlap at one or both ends of the device 100, theinner sleeve 104 will be slightly shorter than the outer sleeve 102.Connecting the inner sleeve 104 to the outer sleeve 102 only via thestruts 116, 116′ permits the inner sleeve 104 to float within the outersleeve 102. Thus, if the device 100 is being utilized with a target bonehaving an intramedullary rod implanted therein, as described above, theinner sleeve 104 is movable relative to the outer sleeve 102 to find theintramedullary rod for cases in which the intramedullary rod is notcentered.

In one embodiment, as shown in FIGS. 3-4, in which the outer and innersleeves 102, 104 are formed via a staggered mesh pattern, each of thestruts 116, 116′ extends from a circumferential strut 131 of the outersleeve 102 to a corresponding circumferential strut of the inner sleeve104 so that joints 130, 131′ connecting the outer sleeve 102 to thestruts 116, 116′ are formed at ends of each of the struts 116, 116′. Inother words, each strut 116, 116′ is connected to one of thecircumferential struts 131 of the outer sleeve 102. As described above,the interstitial mesh 106 is also connected to these struts 116, 116′ sothat the entire device 100 may be spread open via the distal slot 114.It will be understood by those of skill in the art, however, that theouter and inner sleeves 102, 104 may be connected to one another via thestruts 116, 116′ in any of a variety of configurations. For example, inan alternate embodiment as shown in FIG. 5, struts 316, 316′ extendingbetween outer and inner sleeves 302, 304 of a graft containment device300 may connect a circumferential strut of the inner sleeve 304 to theinterstitial mesh 306 without connecting directly to a correspondingcircumferential strut 331 of the outer sleeve 302. In other words, aportion of the corresponding circumferential strut 331 extending betweenan axial strut 332 a immediately adjacent to a distal slot 314 may beremoved to create a torsion type flexural hinge rather than a bendingtype flexural hinge 130, 131′, as described above in regard to thedevice 100.

Since the device 100 may be custom built and printed for a specificpatient, the length, circumference and shape of the outer sleeve 102 maybe customized. For example, the length of the outer sleeve 102 may beselected so that, when the outer sleeve 102 is positioned in the targetarea about the target bone, first and second ends 110, 112 of the outersleeve 102 match the distance separating the portions of bone or so thatthey overlap the bone by, for example, 5 mm on each side. The length ofthe inner sleeve 104 may be selected so that there is a clearancebetween the end surfaces of the separated portions of bone by a selecteddistance (e.g., 2 mm at the first and second ends 146, 148 of the innersleeve 104). It will be understood by those of skill in the art,however, that dimensions of the device 100 may be varied, as desired andsuited for a specific patient. The device 100 may be formed ofbiodegradable polymers such as, for example, polycaprolactone (PCL),which is both printable and bioresorbable.

According to an exemplary method, the device 100 may be custom-built andprinted to suit patient specific bone dimensions and needs. Inparticular, a target bone of a patient may be imaged to obtain bonedimensions such as, for example, circumferences of both an outer surfaceand an inner surface (i.e., corresponding to a medullary canal) of adesired portion of the target bone, along with a length of a portion ofthe bone to be treated (i.e., a distance between separated portions ofthe target bone). These dimensions may be used to enter input data tobuild and print the device 100 using, for example, CAD software. Oncethe device 100 has been built, as described above, the device 100 may bepositioned in the target area between separated portions of the targetbone.

In particular, the device 100 which may have been previously packed withgraft material may be oriented as desired (e.g., by reference to the tag138 with the distal side 124 of the device 100 facing the target bone inwhich an intramedullary rod has been inserted. The outer sleeve 102,interstitial mesh 106 and the inner sleeve 104 may then be opened byseparating spreading the device open via the slot 114. The device 100may then be slid between the separated portions of bone until theintramedullary rod is received in the space 115. At this point, thedevice 100 may be released to permit the slot 114 to close. The surgeonmay then remove the tag 138 and open the outer sleeve 102 at theproximal side 122 of the device 100 to pack additional graft materialinto the space 128 via the widened slot 126. Those skilled in the artwill understand that this embodiment allows the surgeon to open thedevice 100 via the slot 114 at the distal side 124 to slide the device100 into position over an intramedullary rod while permitting thesurgeon to open the device 100 via the slot 126 on the proximal side ofthe device 100 to pack additional graft material therein withoutrotating the device 100. This may be especially useful in a case wherethe inner and or outer sleeves 104, 102, respectively, are asymmetricalfrom the proximal side 122 to the distal side 124. For example, if thedistal side 124 of the device 100 is shorter than the proximal side 122(reflecting a similar asymmetry in the separated portions of bone), thedevice 100 can only be inserted distal side first which would make thesplit inaccessible for later packing of graft material. Thus, a devicesuch as the device 100 with a distal split at the slot 114 and aproximal split at the slot 126 could be inserted distal side first tocapture the intramedullary rod and, when the device has reached thedesired position between the separated portions of bone, the user maypack additional graft material into the device in a way that would notbe feasible without the proximal slot 126.

Graft material may also be inserted at the ends of the device 100,between the first and second ends 146, 148 of the inner sleeve 104 andthe ends of the separated portions of bone. Once the device 100 has beenpositioned as desired, the outer sleeve 102 may be closed by drawing thelongitudinal edges of the outer sleeve 102 adjacent to the slots 114 and126 toward one another and fixing these edges to one another. Forexample, the longitudinal edges may be sutured together to fix thedevice 100 over the target bone. Additional graft material may be packedinto device via the mesh of the outer sleeve 102 after the device 100has been positioned over the bone, as described above.

The overlapping of the first and second ends 110, 112 over ends of theseparated portions of bone and the positioning of the inner sleeve 104between two portions of bone is sufficient to hold the device 100 inposition over the target area of the bone. In particular, theinterstitial mesh 106 and the inner sleeve 104 help to prevent migrationof the device 100 along the bone. In some cases where additionalfixation is desired, however, a user (e.g., surgeon) may insert a bonefixation element (e.g., a bone screw) through one or more of the screwholes 136 formed in the screw receiving structures 134 into theunderlying bone.

In some cases, the user may desire to further customize the device 100during the grafting process. In these cases, the user may cut portionsof the device 100 to accommodate the specific needs of the patient'sbone. The device 100 may be formed of a material that may be cut using,for example, a scissor or other cutting tool. For example, if desired,the user may adjust a length of the outer sleeve 102 to suit a patients'specific needs and/or to create less overlap between the device 100 andthe bone.

FIGS. 6-9 show a graft containment device 200 according to a furtherembodiment of the invention that is substantially similar to the device100 described above except as indicated below. Specifically, the device200 includes first and second ends 210, 212 angled relative to alongitudinal axis L of the device 200 to match a contour of theseparated ends of the bone B between which the device 200 will bepositioned. Thus, the device 200, when positioned as desired between theseparated portions of bone B may be filled with bone graft material sothat the bone graft material may be held in position between theseparated portions of bone B until it has been incorporated into thebone B. In addition, as shown in FIGS. 6 and 7, an intramedullary rod Mextends through the medullary canal of the bone B and across the gapseparating the portions of bone B to connect these portions of bone B toone another. The device 200 comprises an outer sleeve 202 and an innersleeve 204 connected to one another so that, when the device 200 ispositioned in a target area between separated longitudinal portions of atarget bone B, the outer sleeve 202 substantially matches a profile ofthe outer surface of each of the separated portions of bone B while theinner sleeve 204 substantially matches a profile of a medullary canal ofthe target bone and/or a shape of ends of the separated portions of thetarget bone B. The device 200 also comprises an interstitial mesh 206extending radially outward from an exterior surface 208 of the innersleeve 204. The interstitial mesh 206 and the inner sleeve 204 holdgraft material packed therein between the outer and inner sleeves 202,204 and prevent migration of the device 100 along the length of the boneB once the device 200 has been positioned in the target area between theseparated portions of bone B. Similarly to the device 100, the outer andinner sleeves 202, 204 may be formed of a mesh structure and, in oneparticular embodiment, may be formed of a staggered mesh pattern, asdescribed above with respect to the outer sleeve 102. The outer sleeve202, inner sleeve 204 and the interstitial mesh 206 of the device 200are formed via a strut framework so that the device 200 may be threedimensionally built (e.g., by 3-D printing) using patient specific bonedimensions, which may be obtained, for example, via 3D imaging of thetarget bone. In particular, circumferential and/or axial driver curves,along with a desired spacing between adjacent struts, may be used asinput data for building and printing the device 200.

The outer sleeve 202 extends longitudinally from a first end 210 to asecond end 212 and, in this embodiment, defines a generally cylindricalshape with angled ends corresponding to the profile of the outer surfaceof the target bone. The device 200 includes a distal longitudinal slot214 extending radially through the outer and inner sleeves 202, 204,respectively, along an entire length of the device 200 so that thedevice 200 may be opened to be slid over a medullary rod M (or otherinsert) extending between the separated segments of bone B. This permitsthe device 200 to be slid directly over the rod M between the separatedsegments of bone B so that the rod M ends up radially within an innerspace 215 defined by the inner sleeve 204. In other words, struts 216and 216′ extend from the inner sleeve 204 to the outer sleeve 202 andare separated circumferentially from one another to define thelongitudinal slot 214. Those skilled in the art will understand that thedevice 200 may include any number of struts 216 and 216′ separated fromone another longitudinally along the length of the device 200 (i.e.,from the first end 210 to the second end 212) to sufficiently couple theinner sleeve 204 to the outer sleeve 202 while permitting the device 200to open circumferentially as desired. In this embodiment, the struts216, 216′ form the only connection between the outer sleeve 202 and theinner sleeve 204. This permits the outer sleeve 202 to be openedcircumferentially to a large extent (as shown in FIG. 9) to facilitatethe packing of graft material therein. However, those skilled in the artwill understand that additional connections may be made at selectedpoints around the circumference of the device 200 to enhance thestructural integrity of the device 200 although this may reduce theamount by which the outer sleeve 202 may be spread open to pack thegraft material therein. Thus, the device 200 may be spread open at theslot 214 to permit an intramedullary rod M or other implant to be slidinto the device 200 as will be described in more detail below. As willbe understood by those skilled in the art, the first and second ends210, 212, respectively, of the outer sleeve 202 of this embodiment areseparated by a distance substantially equal to a distance by which theportions of bone are separated. As would be understood by those skilledin the art, the first and second ends 210, 212 need not be flat and donot need to have the same general shape. Each of the first and secondends 210, 212 may take any shape necessary to conform to the shape ofthe end of the separated portion of bone to which it will be adjacent.This allows the outer sleeve 202 and the inner sleeve 204 to abut endsof both of the separated segments of bone B. However, alternatively, alength of the outer sleeve 202 may extend slightly beyond the length ofthe inner sleeve 204 so that the outer sleeve 202 over laps one or bothof the ends of the separated portions of bone B. The device 200according to this embodiment also includes a projection 220 at each ofthe first and second ends 210, 212, respectively, with each of theprojections 220 including a hole (not shown) through which a screw orother fastener may be inserted to couple the device 200 to the bone.Those skilled in the art will recognize that either or both of theseprojections 220 may be omitted in favor of other means for securing thedevice 200 to the bone B.

Although the exemplary method describes the device 200 as utilized witha target bone B having an intramedullary rod M implanted therein, itwill be understood by those of skill in the art that the intramedullaryrod M is not a requirement of the device 200. The device 200 may also beutilized with other bone fixation implants such as, for example, a boneplate. Where the device 200 is being used with a bone plate rather thanan intramedullary rod M the inner sleeve 204 may simply be fixed in aclosed configuration via, for example, suturing, prior to closing theouter sleeve 202 about the target bone B. Alternatively, although theinner sleeve 204 is shown and described as forming two clamshellportions separated at the slot 214 and the inner slot 218, the innerslot 218 may be replaced by a living hinge or other structure thatallows the inner sleeve 204 to flex open as necessary to receive theintramedullary rod.

The device 200 according to this embodiment also includes an inner slot218 formed in the inner sleeve 204 diametrically opposed to the slot214. This inner slot 218 enhances the ability of the inner sleeve 204 tospread circumferentially permitting the device 200 to be more easilyopened to the extent necessary to facilitate the insertion of the device200 over the medullary rod M. Those skilled in the art will understandthat this inner slot 218 is optional and may be omitted in any devicethat is sufficiently flexible to accommodate a medullary rod or otherimplant with which it is to be employed without the slot 218.Specifically, the slot 214 allows a surgeon to insert the device 200with the distal side 224 of the device 200 (including the slot 214)facing the bone B. The surgeon may then spread the distal side 224 ofthe device 200 open circumferentially to slide the device 200 over theintramedullary rod M and into position between the separated portions ofbone B. During insertion, the proximal side 222 of the device 200 facesthe surgeon who may then use proximal slot 226 to spread open the outersleeve 202 so that he may pack bone graft material into the annularspace 228 between the outer and inner sleeves 202, 204, respectively,from the proximal side of the device 200.

Specifically, to properly insert the device 200 into the space betweenportions of the bone B separated from one another longitudinally (i.e.,along an axis of the bone) with the medullary rod M extending betweenthese portions of bone B, the distal side of the device 200 is openedcircumferentially via the distal slot 214 and the intramedullary rod Mis passed through the slot 214 until it enters the inner space 215within the inner sleeve 204. The surgeon then allows the device 20 toclose circumferentially (e.g., under its natural bias or by pushing itclosed). Those skilled in the art will understand that, after the device200 has been positioned as desired, it will be held in the closedposition by the surrounding soft tissues. In addition, after theprocedure has been completed, the proximal side 222 of the device 200may then be closed permanently, for example, by suturing. After thedevice 200 has been positioned as desired (but before the proximal side222 of the device 200 has been sutured closed, the surgeon then spreadsthe outer sleeve 202 open circumferentially by spreading apart thehalves 230 of the outer sleeve 202 separated from one another by theproximal slot 226. This permits the surgeon to pack the annular space228 with bone graft material or, if the space was already packed withgraft material, to supplement this material with additional graft (e.g.,to replace any material that may have been lost as the device 200 waspositioned).

The outer sleeve 202 is coupled to the struts 216 and 216′ at joints232, 232′ that are formed to permit the outer sleeve 202 to flex andpivot relative to the struts 216, 216′. That is, the joints 232, 232′permit the halves of the outer sleeve 202 to rotate relative to thestruts 216, 216′, respectively, when the surgeon spreads the halves 230of the outer sleeve 202 apart circumferentially to open the slot 226. Aswould be understood by those skilled in the art, the joints 232, 232′ inthis embodiment form a living hinge to permit the desired rotation ofthe outer sleeve 202 relative to the struts 216, 216′. The struts 216,216′ of this embodiment are also connected to the interstitial mesh 206so that, when the halves 230 of the outer sleeve 202 are spread awayfrom one another at the slot 214, the entire device is spread open—i.e.,the outer sleeve 202, the interstitial mesh 206 and the inner sleeve 204are spread open so that the intramedullary rod M may be passed all theway into the space 215 within the inner sleeve 204.

Although the outer and inner sleeves 202, 204 of the device 200 areshown and described as formed of circumferential and axial struts thatintersect one another, it will be understood by those of skill in theart that the outer and inner sleeves 202, 204 may be formed of any of avariety of mesh structures and patterns so long as the device 200 isformed via a strut framework that will sufficiently contain graftmaterial packed therein.

As would be understood by those skilled in the art, the outer sleeve 202is built via a strut framework so that the outer sleeve 202 is formed ina mesh configuration. The mesh configuration of the outer sleeve 202 ofthe embodiment shown in FIGS. 6-9 includes circumferential struts 234and axial struts 236 intersecting one another. Adjacent circumferentialstruts 234 and adjacent axial struts 236 may be separated from oneanother by a distance of between 0.4 mm to 10.0 mm or any other distancedesired that will provide the desired structural integrity of the device200 and a desired level of containment for the graft material therein.As would be understood by those skilled in the art, the inner sleeve 204may be constructed in substantially the same manner includingcircumferential and axial struts with a similar or different separationas desired. As described above, the length of the outer sleeve 202 maybe selected so that first and second ends 210, 212 of the outer sleeve202 abut the separated ends of the target bone B or so that the ends210, 212 overlap the separated ends of the target bone B by a desiredlength. In addition, one or both of the ends 210, 212 may include ascrew receiving structure 220 projecting axially away from thecorresponding one of the ends 210, 212 to position a screw hole (notshown) thereof at a desired position on the corresponding portion of thetarget bone B. In addition, the device 200 may include a tag (not shown)as described above displaying any desired information (e.g., informationas to whether one or more cages are to be used, lot number, surgeonname, etc.) while also indicating a desired implantation position (e.g.,via text and/or shape with a pointed end of the tag facing a superiorend of the bone), as well as a desired orientation with respect torotation of the device 200 about its longitudinal axis L (e.g., with thetag being mounted on a proximal side 222 of the device 200). When thedevice 200 has been positioned as desired, the tag may be separated fromthe device 200 as described above.

The inner sleeve 204 is connected to the interstitial mesh 206 via aplurality of members 238 so that the inner and outer sleeves 204, 202are separated from one another via the annular space 228. The innersleeve 204 extends longitudinally from a first end 240 to a second end242 and, as described above, defines a shape substantially correspondingto a medullary canal of the target bone and has a length substantiallycorresponding to the distance of separation between the separatedportions of bone B. As would be understood by those skilled in the art,wherein length of the outer sleeve 202 is selected to be equal to adistance between the separated portions of bone B, the inner sleeve 204and the outer sleeve 202 with have the same length. If the outer sleeve202 is lengthened to overlap the bone B at one or both ends of thedevice 200, the inner sleeve 204 will be slightly shorter than the outersleeve 202. Connecting the inner sleeve 204 to the outer sleeve 202 onlyvia the struts 216, 216′ permits the inner sleeve 204 to float withinthe outer sleeve 202. Thus, when the device 200 is utilized with atarget bone having an intramedullary rod M implanted therein, the innersleeve 204 is movable relative to the outer sleeve 202 to fit theintramedullary rod M even when the intramedullary rod M is not centeredin the bone B.

Since the device 200 may be custom built and printed for a specificpatient, the length, circumference and shape of the outer sleeve 202 maybe customized. For example, the length of the outer sleeve 202 may beselected so that, when the outer sleeve 202 is positioned in the targetarea about the target bone B, first and second ends 210, 212 of theouter sleeve 202 match the distance separating the portions of bone B orso that they overlap the portions of bone B by, for example, 5 mm oneach side. The length of the inner sleeve 204 may be selected so thatthere is a clearance between the end surfaces of the separated portionsof bone B by a selected distance (e.g., 2 mm at the first and secondends 240, 242 of the inner sleeve 204). It will be understood by thoseof skill in the art, however, that dimensions of the device 200 may bevaried, as desired and suited for a specific patient. The device 200 maybe formed of biodegradable polymers such as, for example,polycaprolactone (PCL), which is both printable and bioresorbable.

According to an exemplary method, the device 200 may be custom-built andprinted to suit patient specific bone dimensions and needs as describedabove.

The device 200 which may have been previously packed with graft materialmay be oriented as desired (e.g., by reference to the tag with thedistal side 124 of the device 100 facing the target bone in which anintramedullary rod M has been inserted. The outer sleeve 202,interstitial mesh 206 and the inner sleeve 204 may then be opened byseparating spreading the device open via the slot 214. The device 200may then be slid between the separated portions of bone B until theintramedullary rod M is received in the space 215. At this point, thedevice 200 may be released to permit the slot 214 to close. The surgeonmay then remove the tag and open the outer sleeve 202 at the proximalside 222 of the device 200 to pack additional graft material into thespace 228 via the widened slot 226. Those skilled in the art willunderstand that this embodiment allows the surgeon to open the device200 via the slot 214 at the distal side 224 to slide the device 200 intoposition over the intramedullary rod M while permitting the surgeon toopen the device 200 via the slot 226 on the proximal side of the device200 to pack additional graft material therein without rotating thedevice 200. This may be especially useful in a case where the inner andor outer sleeves 204, 202, respectively, are asymmetrical from theproximal side 222 to the distal side 224. For example, as shown in FIGS.6-9, if the distal side 224 of the device 200 is shorter than theproximal side 222 (reflecting a similar asymmetry in the separatedportions of bone B), the device 200 can only be inserted distal sidefirst which would make the distal split inaccessible for later packingof graft material. Thus, a device such as the device 200 with a distalsplit at the slot 214 and a proximal split at the slot 226 may beinserted distal side first to capture the intramedullary rod M and, whenthe device 200 has reached the desired position between the separatedportions of bone B (shown in FIG. 7), the user may pack additional graftmaterial into the device 200 in a way that would not be feasible withoutthe proximal slot 226.

Graft material may also be inserted at the ends of the device 200,between the first and second ends 240, 242 of the inner sleeve 204 andthe ends of the separated portions of bone B. Once the device 200 hasbeen positioned as desired, the outer sleeve 202 may be closed bydrawing the longitudinal edges of the outer sleeve 202 adjacent to theslots 214 and 226 toward one another and fixing these edges to oneanother. For example, the longitudinal edges may be sutured together tofix the device 200 in the desired position over the target bone B.Additional graft material may be packed into device via the mesh of theouter sleeve 202 after the device 200 has been positioned over the boneB, as described above.

The overlapping of the first and second ends 210, 212 over ends of theseparated portions of bone B and the positioning of the inner sleeve 204between two portions of bone B is sufficient to hold the device 200 inposition over the target area of the bone B. In particular, theinterstitial mesh 206 and the inner sleeve 204 help prevent migration ofthe device 200 along the bone B. In some cases where additional fixationis desired, however, a user (e.g., surgeon) may insert a bone fixationelement (e.g., a bone screw) through one or more of the screw holesformed in the screw receiving structures 220 into the underlying bone.

In some cases, the user may desire to further customize the device 200during the grafting process. In these cases, the user may cut portionsof the device 200 to accommodate the specific needs of the patientsbone. The device 200 may be formed of a material that may be cut using,for example, a scissor or other cutting tool. For example, if desired,the user may adjust a length of the outer sleeve 202 to suit a patients'specific needs and/or to create less overlap between the device 200 andthe bone.

It will be understood by those of skill in the art that variousmodification and variations may be made in the structure and methodologyof the present invention, without departing from the spirit or the scopeof the invention. Thus, it is intended that the present invention coverthe modifications and variations of this invention provided that theycome within the scope of the appended claims and their equivalents.

What is claimed is:
 1. A method for positioning a graft containmentdevice, comprising: spreading a distal side of the device opencircumferentially, the device comprising an outer sleeve extendinglongitudinally from a first end to a second end and sized and shaped tocorrespond to a profile of an outer surface of a target bone, the outersleeve including a first proximal longitudinal split extending along alength thereof and a first distal longitudinal split extending along alength thereof, the device comprising an inner sleeve connected to theouter sleeve via at least one strut so that a bone graft collectingspace is defined therebetween, the inner sleeve sized and shaped tocorrespond to a profile of a medullary canal of the target bone, theinner sleeve including a second distal longitudinal split extendingalong a length thereof, the device comprising an interstitial meshextending circumferentially between the inner and outer sleeves to holdgraft material in the bone graft collecting space, the interstitial meshincluding a third longitudinal split extending along a length thereof toform a distal longitudinal slot along the length of the device so that adistal side of the device may be spread open to open the distallongitudinal slot from the outer sleeve, through the interstitial meshand the inner sleeve to a space radially within the inner sleeve;sliding the device over an intramedullary rod so that the inner sleeveis positioned circumferentially around the intramedullary rod and into aspace to be treated by bone graft material; and spreading the firstproximal longitudinal split and packing the bone graft material into thebone graft collecting space.
 2. The method of claim 1, wherein the spaceto be treated extends between cut surfaces of the target bone to replacea resected portion of the target bone.
 3. The method of claim 1, whereinthe inner sleeve includes a second proximal longitudinal split extendingalong at least a portion of a length thereof substantially opposite thesecond distal longitudinal split to facilitate opening of the distallongitudinal slot.
 4. The method of claim 1, wherein the inner sleeve isconnected to the outer sleeve via a plurality of first and secondstruts, the first and second struts being arranged in pairs, the pairsbeing separated from one another along a length of the device with thefirst and second struts of each pair extending radially outward from theinner sleeve on opposite sides of the distal longitudinal slot, at leasta portion of the first and second struts interconnecting the innersleeve, the interstitial mesh and the outer sleeve.
 5. The method ofclaim 4, wherein the interstitial mesh is formed as a plurality of meshmembers extending circumferentially within a space between the inner andouter sleeves, the mesh members being separated from one anotherlongitudinally, at least a first one of the mesh members being connectedto the inner sleeve via a third strut.
 6. The method of claim 4, whereinthe first and second struts are connected to the outer sleeve via aplurality of living hinges permitting the outer sleeve to rotaterelative to the first and second struts.
 7. The method of claim 4,wherein the inner sleeve is connected to the outer sleeve only via thefirst and second struts.
 8. The method of claim 4, wherein the innersleeve further includes a second proximal longitudinal splitfacilitating opening of the distal longitudinal slot.
 9. The method ofclaim 4, wherein the inner sleeve further includes a living hinge formedsubstantially diametrically opposite the distal longitudinal slot tofacilitate opening of the longitudinal slot.
 10. The method of claim 1,wherein the outer sleeve is formed as a plurality of circumferential andlongitudinal members intersecting to define openings of a predeterminedsize.
 11. The method of claim 10, wherein longitudinally adjacent onesof the openings of the outer sleeve are offset relative to one anotherrelative to a longitudinal axis of the device.
 12. The method of claim10, wherein the inner sleeve is formed as a plurality of circumferentialand longitudinal members intersecting to define openings of apredetermined size.
 13. The method of claim 12, wherein longitudinallyadjacent ones of the openings of the inner sleeve are offset relative toone another relative to a longitudinal axis of the device.
 14. Themethod of claim 1, further comprising a tag releasably attached to aproximal side of the device, a shape of the tag indicating a desiredimplantation orientation of the device.
 15. The method of claim 1,wherein the first distal and proximal longitudinal splits extend alongan entire length of the outer sleeve and wherein the second longitudinaldistal split extends along an entire length of the inner sleeve.
 16. Themethod of claim 1, wherein the distal longitudinal slot is formed by analignment of the distal longitudinal splits of each of the outer sleeve,inner sleeve, and interstitial mesh.
 17. A method for positioning agraft containment device, comprising: spreading a distal side of thedevice open circumferentially, the device comprising a radially innersleeve dimensioned and shaped to substantially match dimensions of amedullary canal of a portion of bone to be treated, the devicecomprising an inner sleeve including an inner distal split extendinglongitudinally along a length thereof, an interstitial structureincluding a plurality of circumferential members extending radiallyoutside and circumferentially around at least a portion of the innersleeve, the plurality of circumferential members being separated fromone another longitudinally along the device, the interstitial structureincluding a distal interstitial split along a length thereof; an outersleeve extending circumferentially outside and around the interstitialstructure, the outer sleeve including a distal outer split along alength thereof and a proximal outer split along a length thereof, thedevice comprising a plurality of pairs of radial struts, a first one ofeach pair of struts being coupled to the inner and outer sleeves on afirst side of the inner and outer distal splits while a second one ofeach pair of struts is coupled to the inner and outer sleeves on asecond side of the inner and outer splits, the pairs of radial strutsbeing separated from one another longitudinally along the device;sliding the device over an intramedullary rod so that the inner sleeveis positioned circumferentially around the intramedullary rod and into aspace to be treated by bone graft material; and spreading the firstproximal longitudinal split and packing bone graft material into thebone graft collecting space.
 18. The method of claim 17, wherein thespace to be treated extends between cut surfaces of the target bone toreplace a resected portion of the target bone.
 19. The method of claim17, wherein at least a portion of the pairs of radial struts areconnected to corresponding ones of the circumferential members.
 20. Themethod of claim 19, further comprising a plurality of connection membersinter connecting the inner sleeve and the circumferential members, theinner sleeve being connected to the outer sleeve only via the radialstruts.